Weird grinding when braking

So whenever I brake while reversing (and rarely while moving forwards) I hear this odd grinding noise coming from the front left wheel and can feel it through the brake. Im not a petrol head but I decided to replace a wheel bearing hub myself recently to save money. Im pretty sure I reconnected the anti lock brakes correctly though I doubt it's that. Any suggestion as to what it could be? (As for the obvious. Yes my brakes are good)

Jack it up and turn wheel slowly- chances are good the splash shield is bent into rotor- needs clearance to spin freely-

or you may have a brake squealer letting you know you have worn out pads- since it only does it with brakes applied.

Jack it up and turn wheel slowly- chances are good the splash shield is bent into rotor- needs clearance to spin freely-

or you may have a brake squealer letting you know you have worn out pads- since it only does it with brakes applied.. Agreed, no quick diagnosis here.

Jack it up and turn wheel slowly- chances are good the splash shield is bent into rotor- needs clearance to spin freely-

or you may have a brake squealer letting you know you have worn out pads- since it only does it with brakes applied.
I did notice that the shield was slightly bent when I replaced the wheel bearing hub. It's rusted to hell though so I wonder I I can't just take it off for good.

Inspect the shield for signs of contact,scraping with the rotor.Check for looseness. It can be bent back into shape if necessary to get clearance from rotor. Unless its rusted through and the metal is weak I'd leave it alone. The shield is extremely necessary to keep excess water,snow and debris clear of the spinning rotor,brake caliper and ABS tone ring. Do not eliminate it.